#include <fstream>
#include <algorithm>

using namespace std;

const int NMAX = 100000 + 5;
const int VALMAX = 1000000 + 5;
typedef long long int lint;

int N, K;
int v[NMAX];

lint cnt(lint groups) {
    lint sum = 0;
    for (int i = 1; i <= N; ++ i)
        sum += min(1LL * v[i], groups);
    return sum;
}

int main()
{
    ifstream cin("grupuri.in");
    ofstream cout("grupuri.out");

    cin >> K >> N;
    for (int i = 1; i <= N; ++ i)
        cin >> v[i];

    lint st = 1;
    lint dr = 1LL * NMAX * VALMAX;
    lint ans = 0;

    while (st <= dr) {
        lint mid = (st + dr) >> 1;
        if (cnt(mid) >= mid * K) {
            ans = mid;
            st = mid + 1;
        }
        else
            dr = mid - 1;
    }

    cout << ans << '\n';
    return 0;
}